Because of its rapid turnaround time, fluorescent in situ hybridi...

Question

Because of its rapid turnaround time, fluorescent in situ hybridization (FISH) is commonly used in hospitals and laboratories as an aneuploid screen of cells retrieved from amniocentesis and chorionic villus sampling (CVS). Chromosomes 13, 18, 21, X, and Y (see Chapter 8) are typically screened for aneuploidy in this way. Explain how FISH might be accomplished using amniotic or CVS samples and why the above chromosomes have been chosen for screening.

Accepted Answer

Hi everyone. Let's look at our next question. It says what is the significance of fluorescence in C. Two hybridization or F. I. S. H. In investigating chromosomes, let's recall what this technique is. You kind of have a key from the name here. But it's a technique in which a specific DNA sequence can be detected and located in a chromosome using a primer tag the fluorescence. I have a primer that's complementary to the sequence you're looking for. And that primer has a fluorescent tag on it. So with that in mind let's look through our answer choices here, noting that we're looking for the significance of this in investigating chromosomes. Choice A says it is used to artificially synthesized DNA. Well that is not correct. Just locates a sequence. Makes a small primer that binds to a complementary sequence. Doesn't synthesize DNA. Choice B says it records cell division. Well this would not be the main purpose of it. Uh Scientists use a stain to stain the different to stain the chromosomes and see visually see their progress through cell division choice C says it detects and locates a specific DNA sequence. And this is our answer choice. As we said, the valuable um aspect of it is that it can find with this florescent tag and its specificity a specific DNA sequence among all the chromosomes. So you can see the physical location of a gene on a chromosome with this technique it doesn't even have to be a whole gene. It can be just a particular sequence and then finally Choice. D. Says it determines the exact length of the whole genome. And that's not correct. Since it just binds to this one D. N. A sequence that isn't what you'd use it for. If you want to determine the length of the whole genome, you would actually look for the mass of D. N. A. In the nucleus which you could then use um the you could convert to the number of base pairs in that genome just by looking at the mass of D. N. A. And the nucleus. So again, what is the significance of fluorescence and see two hybridization or F. I. S. H. In investigating chromosomes? And that's choice C. It detects and locates a specific DNA sequence in the next video?

Key Concepts

Fluorescent In Situ Hybridization (FISH)

Aneuploidy

Amniocentesis and Chorionic Villus Sampling (CVS)

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